超临界二氧化碳闭式布莱顿循环系统研究进展

超临界二氧化碳(SCO₂)闭式布莱顿循环凭借高热效率、高紧凑性和高经济-环保性等优势，已成为能源与动力领域的热点技术之一。针对超临界二氧化碳闭式布莱顿循环，详细介绍了工作原理、优势及国内外相关研究进展，总结了循环总体热力、超临界工质叶轮机、紧凑高效换热器、控制及储热等相关关键技术的研究现状，并对当前工程应用面临的问题和未来技术发展方向进行了分析和展望。分析表明，循环总体热力设计阶段应涵盖部件低维性能分析，以评估部件性能指标的可实现性，并综合考虑全寿命周期性能、紧凑性、经济性等指标。工质的剧烈物性变化导致叶轮机与换热器内部特殊流动与换热机理，需发展充分考虑工质特殊物性影响的叶轮机和紧凑换热器设计方法；通过理论分析和机器深度学习相结合构建不同工质叶轮机相似方法，可为超临界二氧化碳叶轮机气动性能试验验证提供理论基础。此外，鲁棒高效的控制策略可实现超临界二氧化碳闭式布莱顿循环有效可靠调控，而集成新型介质储热技术的超临界二氧化碳闭式布莱顿循环系统将为高温光热发电提供关键技术支撑。 

Progress in research of closed supercritical carbon dioxide Brayton cycle system

The supercritical carbon dioxide (SCO₂) closed Brayton cycle has received considerable attention in the field of energy and power due to its advantages of high thermal efficiency and compactness, economy, and environment friendliness. This study reviews research on the SCO₂ closed Brayton cycle in terms of its operating principle, advantages, and domestic and overseas research progress. Key techniques such as cycle thermodynamics, turbomachinery working with supercritical medium, high-efficiency compact heat exchangers, control strategies, and thermal storage are analyzed. Moreover, difficulties in and challenges of engineering applications are discussed, and future development directions are presented. It is indicated that the low-dimensional performance analysis of components should be involved in the conceptual design of cycle thermodynamics to estimate the attainable performance of components, considering the lifecycle performance, compactness, and economy of the cycle. The dramatic variations of working medium properties would lead to special flow and heat transfer mechanisms in turbomachinery and heat exchanger, respectively, motivating the design methodologies for turbomachinery and compact heat exchanger that fully consider the effect of special properties of working medium. The similarity method constructed by theoretical analysis and deep machine learning could provide theoretical foundations for experimental validation of the aerodynamic performance of SCO₂ turbomachinery. Furthermore, robust and efficient control strategies could control the cycle effectively, and SCO₂ closed Brayton cycles integrated with thermal storage techniques adopting novel thermal medium would provide key technical supports for concentrating solar power at high operation temperature.